Assessing wildfire impact on Trigonella elliptica habitat using random forest modeling.

Wildfires have a significant impact on ecosystems worldwide, especially on the degradation of arid and semi-arid rangelands. This research focuses on assessing the effects of wildfires on the habitat of Trigonella elliptica, a valuable herb species found in the central rangelands of Iran. To achieve this, the Random Forest (RF) algorithm has been deployed to predict T. elliptica habitat and fire hazard using socio-environmental variables in Yazd province, Iran. 225 fire points and 103 habitat locations were used for model training and testing. The IncNodePurity index and Probability Curves (PC) have been utilized to determine the influence of socio-environmental variables. The combination of the prediction maps of the habitat and wildfires pointed out the possible damage due to fire. The high performance of the RF model is confirmed by the area under the curve (AUC) and the true skill statistic (TSS) values (0.90 and 0.81 for the habitat; 0.92 and 0.82 for the wildfire). The importance assessment of variables revealed that elevation, slope, and precipitation are the most influential variables in the distribution of T. elliptica, while distance to roads, population density, and wind speed are the key factors affecting wildfire occurrence. In the final map, a comparison of different regions of T. elliptica habitat under fire hazard with fire-free habitats using Kruskal-Wallis and Dunn tests indicated that the fire hazard in the T. elliptica habitat is a serious concern. Since the areas with the highest fire hazard and the highest presence of T. elliptica cover approximately 2311.38 km2, neglecting these regions could lead to the gradual reduction of T. elliptica, and create conditions for secondary succession dominated by less valuable annual species. The findings of this study underscore the importance of implementing fire management strategies, protection projects, and continuous monitoring to ensure the safety and conservation of the T. elliptica habitat.

Chelate facilitated phytoextraction of Pb, Cd, and Zn from a lead-zinc mine contaminated soil by three accumulator plants.

This study aims to evaluate the enhancement of phytoextraction of heavy metals (Pb, Cd, and Zn) by species Marrubium cuneatum, Stipa arabica, and Verbascum speciosum, through EDTA amendment. Assisted phytoextraction pot experiments were performed at different EDTA dosages (0, 1, 3, and 5 mmol kg-1 soil). The DTPA-extractable metal content increased in the presence of EDTA, followed by their contents in the tissues of all three studied species. Resulting from oxidative stress, the activity of antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) increased when the chelating agent was added. EDTA in higher doses partially decreased chlorophyll concentration, and 5 mmol kg-1 of that reduced the biomass of the studied species. The bioconcentration factor (BCF) for Cd was notably high in all studied plants and considerably elevated for Zn and Pb with the addition of EDTA in M. cuneatum and S. arabica (BCF > 1), whilst an accumulation factor greater than one (AF > 1) was found for Cd in all species and for Pb in the case of S. arabica. In general, the results demonstrated that EDTA can be an effective amendment for phytoextraction of Cd, Zn, and Pb by M. cuneatum, V. speciosum and S. arabica in contaminated soils.

Investigating metal pollution in the food chain surrounding a lead-zinc mine (Northwestern Iran); an evaluation of health risks to humans and animals.

The current study aims to evaluate the health risk of heavy metals for humans and animals in the Angouran mining complex (northwest of Iran). Twenty-five plant species and their corresponding soils (natural soils) were collected along with mine tailings samples. The carcinogenic and non-carcinogenic risks of heavy metals (Zn, Pb, Cd, Cr, and Co) for humans using the hazard quotient (HQ) and hazard index (HI) were evaluated. Moreover, the health risk caused by forage feeding to grazing ruminants (cow and sheep) and the risk associated with animal products consumption by humans in the soil-plant-animal transfer system were assessed. The value of HI in natural soils (rangeland use) was less than one (HI < 1), while regarding tailings, the HQ via oral ingestion and the HI were greater than one (HI & HQ > 1). The range of total carcinogenesis risk in natural soils exceeded the target risk (Risk < 10-6) and for tailings, it showed the probability of cancer risk, 1 person per 3636 populations, which is much higher than the acceptable or tolerable range (10-4 < Risk < 10-6). Regarding the animal health risk, the content of Pb and Cd in most of the animal organs was higher than the control values. In turn, dietary exposure to Pb and Cd is worrying for residents due to exceeding the provisional tolerable weekly intake (PTWI). This comprehensive study suggests the necessity of risk assessment of mining sites in Iran and immediate control measures to diminish pollutants.

Perspectives for phytoremediation capability of native plants growing on Angouran Pb-Zn mining complex in northwest of Iran.

Phytoremediation is a cost-effective, environmentally-friendly and emerging remediation technology that treats polluted areas using plants, having the potential to restore ecosystems and make compromised areas useable again, therefore returning a resource to community use. In the present work a study was conducted on the contamination of soil by heavy metals (Zn, Pb, Cr, Cd, and Co) in the mining area of Angouran (northwestern Iran) and on their uptake by 25 native species present in the mining district, in order to evaluate their potential use in phytoremediation interventions. Plant and soils from three sites around the mine were sampled and characterized, and metals accumulation and translocation were evaluated. Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied to study the behavior of species in the accumulation and translocation of the elements in their tissues. The contents of Zn, Pb, Cr, Cd, and Co in the studied plants were, respectively, 31.77-723.05, 7.78-233.25, 1.77-21.57, 0.04-7.92, and 0.15-9.97 mg/kg. Among the 25 species, 13 plants showed translocation factor greater than one (TF > 1) for Zn, 14 for Pb, 3 for Cr, 10 for Co, and 6 for Cd. Marrubium cuneatum having an accumulation factor greater than one (AF > 1) for Zn and bioconcentration factor greater than one (BCF >1) for Cd can be considered as an accumulator and stabilizer for Zn and Cd, respectively. Also, the highest value of Pb (233.25 mg/kg) and Cr (21.57 mg/kg) were found in the shoot of this plant. Psathyrostachys fragilis with BCF >1 for Co and maximum Pb accumulation in the root can be used as a stabilizer plant for Pb and Co-contaminated soils. Besides, Stipa arabica and Verbascum speciosum, with TF > 1 and rather high AF, could be considered suitable species for removing Zn and Pb through phytoextraction. This research showed that some native species in the study area have considerable potential for developing phytoremediation strategies.

Phytoremediation ability of H. strobilaceum and S. herbacea around an industrial town.

Contaminations of soil and water resources with various organic and inorganic compounds are of great importance on account of the close relationship between the living organisms and their feeding. That is due to direct impact in supplying food for living organisms in terms of environmental and human health aspects. In this regard, the present study aimed to investigate the phytoremediation potential of H. strobilaceum and S. herbacea in contaminated soils. For this purpose, soil and plant samples were collected from around the sewage channel in Eshtehard industrial region of Iran. Sampling started at the edge of the channel and ended in a distance of 500 m from the channel. The distance of 1000 m from channel was considered as the control point. ICP-OES was used for the measurement of heavy metals. The obtained results showed that the highest and lowest amounts of soil lead (Pb) were 17.6 and 2.33 mg kg-1, respectively. For Cadmium (Cd), the values ranged from 0.341 to 0.11 mg kg -1 at 21-50 cm depth for the control point. For the plants, the highest and lowest amount of Pb belonged to H. strobilaceum shoot (10.38 mg kg -1) and S. herbacea root (7.54 mg kg -1), respectively. The maximum (1.64 mg kg-1) and minimum (0.36 mg kg-1) Cd concentration was observed in the root and shoot of H. strobilaceum, respectively. In both species, Translocation Factor (TF) for Pb and Cd was greater than 1 and less than 1, respectively. Cd Bio Concentration Factor (BCF) in the roots of both species was estimated to be greater than 1 while for Pb, this index was smaller. Bio Accumulation Factor (BAF) in the shoots of Pb and Cd for both plants were lower and greater than 1, respectively. In general, the results revealed that the highest concentrations of Cd and Pb are absorbed and stored by the underground organs of H. strobilaceum and S. herbacea and these plants have the ability to remove Pb and Cd from contaminated soils.

Changes in the essential oil content and composition of Salvia limbata C.A. Mey at different growth stages and altitudes.

Salvia limbata is of great importance to the pharmaceutical industry owing to its various biological effects. Therefore, it is important to investigate the main factors that affect its essential oil composition. Although some investigations have been performed with regard to the phytochemistry of S. limbata, this study investigates, for the first time, the effect of growth stage and altitude on the content and chemical composition of essential oil extracted from S. limbata. For this purpose, the essential oil was extracted from 45 air-dried samples by hydrodistillation and analyzed by GC-MS and GC-flame methods. The highest content of essential oil was obtained from aerial parts in the vegetative stage at an altitude of 1500 m (0.86% v/w). Our findings show that the vegetative stage at 1500 m is the optimal harvest time to extract the highest content of oil while the highest content of monoterpenes (including α-pinene and ß-pinene) could be obtained in the same phenological stage at 2000 m. By contrast, the content of sesquiterpenes increased to the highest values in the ripening stage at 1500 and 2500 m. The results of this study help to find the optimal conditions to obtain the highest content of S. limbata essential oil, but additional studies are warranted.

Study of antioxidant activity and some herbal compounds of Dracocephalum kotschyi Boiss. in different ages of growth.

OBJECTIVE: Dracocephalum kotschyi Boiss is one of eight species of Dracocephalum, an endemic species of Iran, and grows in areas such as Isfahan, Yasuj, Mazandaran, and Tabriz. The present study was designed to analyze the antioxidant, phenol and flavonoids contents of this plant under different conditions of cultivation in a completely randomized, factorial design. MATERIALS AND METHODS: Shrubs of different ages (two, three, and six) in cultivated rangeland collected from three randomly plant at the end of May 2018 simultaneously with the flowering time. Antioxidant activity of methanolic extract of plant samples were evaluated with DPPH method. Total phenolic compounds and the total content of flavonoids were measured using the Folin Sioukhlu and aluminum chloride methods respectively. RESULTS: The result showed that there was a significant effect of planting time, plant organs and interaction of time and organ on the total antioxidant capacity and total phenol and flavonoids contents. The highest antioxidant activity, total phenol, and total flavonoid have belonged to the flower of six age plants. The highest antioxidant activity, total phenol, and total flavonoid have belonged to the flower of six age. The highest level of antioxidant activity with IC50 15.8489 ±â€¯0.001 µg/ml belonged to the flower of the two-year-old plant, which has a stronger antioxidant activity than the BHT standard with 19.95 µg/ml. CONCLUSION: But in general, it can be said that the six-year-old plant with the highest antioxidant capacity, phenolic, and flavonoid compounds is the best age and mainly flower organ is preferred.

Effects of ecological factors on the antioxidant potential and total phenol content of Scrophularia striata Boiss.

Scrophularia striata, commonly known as figwort, is one of the most important medicinal plants that mainly grows in cold regions of the Zagros Mountains (West of Iran). Although the chemical composition of this plant species has not yet been explored, people living in Ilam province (W Iran) have used it for many years to treat different illnesses. The present study aims to analyze the effect of some ecological factors on the antioxidant potential and the amount of phenol present in this plant species, using a random factorial design with two factors (elevation and region) and three replicates. The fruits of the plant were gathered from three different elevations. They were collected from three regions of the Ilam province (Badreh, Dareshahr, and Dehloran) in June 2016, when the fruits appear. Moreover, to analyze different soil chemical and physical features, soil samples were gathered from a depth of 0.5 m under the shrubs. The antioxidant action of the methanol extract from the plant samples and the total amount of phenol compounds were measured using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and the Folin-Ciocalteu method, respectively. The results showed that the effects of site and elevation, and the interaction between these factors, on the antioxidant potential and total phenol amount were significant with a probability of error of 1%. The maximum extract efficiency (19.37 ± 3.07%), antioxidant potential (126.5656 ± 0.96 µg/mL), and total amount of phenol (55.7689 ± 3.17 µg/mL) were obtained from Dareshahr at an elevation of 600 m above mean sea level. The minimum amount of total phenol (24.6544 ± 3.21 µg/ml) was recorded at the lowest elevation of Badreh, at which phosphorus, potassium, organic carbon, organic material, nitrogen, acidity, lime, and silt were present at the lowest amount. However, the antioxidant activity and total amount of phenol had a strong direct correlation in the two districts of Dareshahr and Badreh, but were reversely and strongly correlated in Dehloran. Therefore, it can be stated that Scrophularia striata has the potential for antioxidant activity, however, the complexity of the effect of ecological factors on one hand, and the emergence of different chemical processes in the plant under such effects on the other hand, has led to the synthesis of different compounds with antioxidant potential in the plant in different regions.

Morphophysiological changes of wild Stachys multicaulis species under physical conditions during the cultivation process.

Depending on the physical environmental conditions, cultivation process can have significant effects on the wild plants' morphophysiological characteristics. Stachys multicaulis is an Iranian wild endemic medicinal plant species and its cultivation preformed under different Soil Textures (ST) and Soil Moisture Regimes (SMRs). Controlled pot culture conditions performed with light, moderate, heavy STs and a set of SMRs at 100% Field Capacity (FC), 70%FC and 30% FC. Plant cultivated in heavy STs had higher performance in all measured treats. Height of plant (HP), Calibrated Greenness (CG), Leaf Ratio (LR) and Angle (LA), aerial Moisture Content (MC) did not show a regular trend in comparison to the wild. Unlike the Density of Trichome (DT), Length of leave's Trichome (LT) showed a significant change under cultivation conditions (p < 0.01). Also, as a physiological response, Essential Oils Components (EOC), especially thymol and bicyclogermacrene decreased with decreasing soil MC for light ST and the lowest change were observed in heavy ST and 30%FC. Generally, cultivation reduced EOCs, but improved plant's morphological characteristics.

Monitoring and assessment of seasonal land cover changes using remote sensing: a 30-year (1987-2016) case study of Hamoun Wetland, Iran.

The availability of Landsat data allows improving the monitoring and assessment of large-scale areas with land cover changes in rapid developing regions. Thus, we pretend to show a combined methodology to assess land cover changes (LCCs) in the Hamoun Wetland region (Iran) over a period of 30-year (1987-2016) and to quantify seasonal and decadal landscape and land use variabilities. Using the pixel-based change detection (PBCD) and the post-classification comparison (PCC), four land cover classes were compared among spring, summer, and fall seasons. Our findings showed for the water class a higher correlation between spring and summer (R2 = 0.94) than fall and spring (R2 = 0.58) seasons. Before 2000, ~ 50% of the total area was covered by bare soil and 40% by water. However, after 2000, more than 70% of wetland was transformed into bare soils. The results of the long-term monitoring period showed that fall season was the most representative time to show the inter-annual variability of LCCs monitoring and the least affected by seasonal-scale climatic variations. In the Hamoun Wetland region, land cover was highly controlled by changes in surface water, which in turn responded to both climatic and anthropogenic impacts. We were able to divide the water budget monitoring into three different ecological regimes: (1) a period of high water level, which sustained healthy extensive plant life, and approximately 40% of the total surface water was retained until the end of the hydrological year; (2) a period of drought during high evaporation rates was observed, and a mean wetland surface of about 85% was characterized by bare land; and (3) a recovery period in which water levels were overall rising, but they are not maintained from year to year. After a spring flood, in 2006 and 2013, grassland reached the highest extensions, covering till more than 20% of the region, and the dynamics of the ecosystem were affected by the differences in moisture. The Hamoun wetland region served as an important example and demonstration of the feedbacks between land cover and land uses, particularly as pertaining to water resources available to a rapidly expanding population.

Investigating the Role of Wind in the Dispersion of Heavy Metals Around Mines in Arid Regions (a Case Study from Kushk Pb-Zn Mine, Bafgh, Iran).

The Kushk Pb-Zn mine is located in Central Iran and it has been in operation for the last 75 years. To investigate the role of wind dispersion of heavy metal pollutants from the mine area, dust samples were collected during 1 year and topsoil samples were collected around the mine. Results showed that the topsoil is polluted with Pb and Zn to about 1500 m away from the mine. It was also found that there was not a significant difference between the metal concentrations in topsoil and dust samples. The Pb and Zn concentrations in the dust samples exceeded 200 mg kg-1 and their lateral dispersion via wind was estimated to be about 4 km away from the mine. It has been shown that a combination of mining activities and mechanical dispersion via water and wind have caused lateral movement of heavy metals in this area.

Investigating lead and zinc uptake and accumulation by Stipa hohenackeriana trin and rupr. in field and pot experiments / Investigação sobre a captação e acúmulo de chumbo e zinco por Stipa hohenackeriana trin. & rupr. em experimentos de campo e em vaso

This study was conducted to evaluate Pb and Zn uptake, mobility, and accumulation in Stipa hohenackeriana using field soil in pot and field experiments. Moreover, the effects of Municipal Solid Waste Compost (MSWC) (0, 1, and 2%) and Nano-Silica (NS) (0, 250, and 500 mg/kg) on Stipa biomass, Pb and Zn availability in the soil, and Pb and Zn uptake and accumulation were studied using pot experiments. Samples of soil, root, and shoots of Stipa were collected from field and greenhouse and after drying, extraction of Pb and Zn was done by acid digestion. Bio- Concentration Factor (BCF) and Translocation Factor (TF) were calculated to determine Pb and Zn phytoremediation efficiency. The amount of Zn and Pb remediation by Stipa from soil was determined by remediation factor (RF). The results of field experiments showed the Pb and Zn level decreased in the order of: soil >shoot>root. Results of the pot experiments also showed that plants grown in NS500-amended pots had 33% and 32% higher Pb in roots and shoots compared to control pots, respectively. In comparison, roots Pb concentration in pots amended with MSWC1% and MSWC2% decreased 22.4% and 1.7%, respectively. Roots and shoots Zn concentration in NS500-amended pots was 5.6% and 6.5% higher, respectively. However, root Zn concentration in treatments of MSWC1% and MSWC2% decreased 52.3% and 39.4%, respectively. Shoots Zn concentration decreased 52.5% and 40.0%, respectively. Although MSWC decreased the uptake and accumulation of Pb and Zn in Stipa roots and shoots, it improved the plant growth and consequently increased RF and soil remediation compared to the NS. Thus, it seems that applying MSWC and NS simultaneously can be a suitable strategy for the purpose of improving phytoremediation capability of Stipa in the Pb and Zn contaminated soils. In general, Stipa can be a suitable candidate for the accumulation of heavy metals, especially for Pb and Zn contaminated soils.

Este estudo foi conduzido para avaliar a absorção, mobilidade e acumulação de Pb e Zn em Stipa hohenackeriana em experiências usando solo de campo em vaso e em campo. Além disso, os efeitos do Composto Municipal de Resíduos Sólidos (MSWC) (0, 1 e 2%) e de nanopartículas de sílica (NS) (0, 250 e 500 mg/kg) na biomassa de Stipa, na disponibilidade de Pb e Zn no solo, e na absorção e acúmulo de Pb e Zn foram estudados usando experiências em vaso. Amostras de solo, raiz e brotos de Stipa foram coletadas do campo e da estufa e, após a secagem, a extração de Pb e Zn foi feita por digestão ácida. O Fator de Bioconcentração (BCF) e o Fator de Translocação (TF) foram calculados para determinar a eficiência de fitorremediação de Pb e Zn. A quantidade de remediação de Zn e Pb pela Stipa a partir do solo foi determinada pelo Fator de Remediação (RF). Os resultados das experiências de campo mostraram que o nível de Pb e Zn diminuiu na seguinte ordem: solo > broto > raiz. Os resultados das experiências em vaso também mostraram que as plantas cultivadas em vasos corrigidos com NS500 apresentaram teores de Pb 33% e 32% maiores em raízes e brotos em comparação com vasos de controle, respectivamente. Em comparação, a concentração de Pb em raízes em vasos corrigidos com MSWC1% e MSWC2% diminuiu 22,4% e 1,7%, respectivamente. A concentração de Zn em raízes e brotos em vasos corrigidos com NS500 foi de 5,6% e 6,5% maior, respectivamente. No entanto, a concentração de Zn da raiz nos tratamentos de MSWC1% e MSWC2% diminuiu 52,3% e 39,4%, respectivamente. A concentração de Zn nos brotos diminuiu 52,5% e 40,0%, respectivamente. Embora o MSWC tenha diminuído a absorção e acumulação de Pb e Zn nas raízes e brotos de Stipa, melhorou o crescimento da planta e consequentemente aumentou o RF e a remediação do solo em relação ao NS. Assim, parece que aplicar MSWC e NS simultaneamente pode ser uma estratégia adequada com o objetivo de melhorar a capacidade de fitorremediação de Stipa nos solos contaminados com Pb e Zn. Em geral, a Stipa pode ser um candidato adequado para a acumulação de metais pesados, especialmente para solos contaminados com Pb e Zn.